The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
In the case of hybrid vehicles, regenerative braking is typically performed using a motor directly connected to wheels to control a braking force of the motor to be continuously transferred to the wheels, thereby improving fuel efficiency.
That is, when a driver steps on a brake while driving a vehicle, electricity is generated by the regenerative braking of the motor to charge a battery. Therefore, the charged power of the battery is used as a power source that may output power when the vehicle restarts. Therefore, the regenerative braking of the motor plays an important role in fuel efficiency, which is identically applied even in a shifting section of the transmission.
However, we have discovered that when the clutch of the transmission is initially released during the regenerative braking, the braking forces of a vehicle are lost despite the divers pushing of the brake, and therefore the vehicle is in a risky diving mode with reduced diving stability of the vehicle.
For example, we have found that when the regenerative braking torque is suddenly changed during power off down shifting, and thus the change in input torque of the transmission is excessive, an engagement side clutch torque is not sufficient, and therefore a summed torque of the engagement side clutch and a release side clutch becomes lower than the input torque of the transmission, such that the releasing of the clutch may occur.
The contents described as the related art have been provided only to assist in the understanding of the background of the present disclosure and should not be considered as corresponding to the related art known to those skilled in the art.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.